Sterilizer



A. H. JESSUP.

STERILIZER.

APPLICATION FILED FEB. a, 1920. 1,392,944. Patented Oct. 11, 1921.

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STERILIZER.

APPLICATION FILED FEB. 3, 920. 1,392,944, Patented Oct. 11, 1921.

' 2 SHEETS-SHEET 2. 36 :10 39 01/ 11 ,a/ .1 59 a 55 uvmwroze %zfs A TTOR/VE)" ALBERT H. JESSUP, OF ERIE, PENNSYLVANIA, ASSIGNOR TO COMPANY, OF ERIE, PENNSYLVANIA, A CORPORATION AMERICAN STERILIZEB OI PENNSYLVANIA.

STERILIZER.

Original application and July 5, 1917, Serial No. 178,535. Divided and this a, 1920. Serial No. 355,910.

To all whom itmay concern:

Be it known that I, ALBERT H. JESSUP, of Erie, in the county of Erieand State of Pennsylvania, have invented certain new and useful Improvements in Sterilizers; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings,forming a part of this specification, and to the reference-numerals marked thereon.

This invention relates mainly to heating elements such as are used in' electrically heated sterilizers adapted for general use, but more particularly designed for sterilizing surgical instruments and dressings.

his application is a division of my copending patent a plication filed July 5, 1917, and having erial No. 178,535.

One object of the invention is to provide an improved heating element especially adapted for use in connection with sterilizers. In a'preferred embodiment of the invention hereinafter described, I employ a plurality of resistance strips so woven or laced upon and across an insulating support that one strip is never in contact with the other While each strip presents nearly its entire surface for uniform heating efi'ect over practically the entire area of the insulating support which is disposed to hold the strips in close heating contact with a wall of the vessel containing the sterilizing fluid or agent. In some features, the invention is applicable to sterilizers having but one resistance strip laced upon an insulating support. The improved disposal of the resistance strip or strips upon the insulating support avoids loss of electric energy incident to use of helically wound resistance strips and maintains an even distribution of heat over practically the whole area of the opposed receptacle wall. A further object is to provide a system of leads, contacts, switch terminals and wipers adapted to effect either series or parallel connections of the resistance strips with the energizing circuit and to place one strip in'circuit and disconnect the other, for regulating the degree of heat imparted to the sterilizing fluid or agent in the sterilizer receptacle. To these and other ends the invention resides in cer- Specification of Letters Patent.

9 of insulating Patented Oct. 11,1921.

application filed February tam improvements and combinations of parts, all as w1ll be hereinafter more fully descrlbed, the novel features being pointed out in the cation.

In the drawings:

F'1gure 1 is a central longitudinal sectional elevation of a sterilizer embodying the nvention;

Fig. 2 is an enlarged central transverse vert cal sectional view thereof;

F 1g. 3 1s a top plan view of the electric heating element and its leads and binding posts, and a dia ram of the wiring connections thereto an switch, and

Figs/1, 5 and 6 show different adjustments of the switch, for varying the .electric current to the heating element.

Similar reference numerals throughout the several views indicate the same arts.

In the illustrated development 0 the invention as embodied in a sterilizer, the numeral 1 indicates the sterilizing fluid receptacle mounted on legs 2, and having at one end a drain cock 3 connected at an outlet 4 in the receptacle bottom plate 5, against the lower .face of which is held an electrically insulating but heat conducting sheet or plate 6, preferably of mica, said parts 5, 6, together forming a laminated bottom for the receptacle 1. Said plate 5 preferably has a pendent edge flange 7 forming below the bottom a chamber 8 containing the heatmg element comprising a plate or support material and in this instance, two separate resistance heating strips 10, 11, peculiarly wound or woven upon and across the support 9, as hereinafter more fully explained. Said strips 10, 11 are pressed against the mica plate 6 by bolts 12 fixed to the support 9, and having nuts 13 which act upon a cover plate 14 shown closely underlying the support 9, and forming a bottom for the heat conserving chamber 8. The plate 14 may be made of insulating mica or of metal.

Within the receptacle 1 is laced a vertically movable instrument ho ding tray 15 having opposite end angular connections 16 the vertlcal parts of which move within guides 17 on the receptacle end walls, and

to the current controllingclaims at the end of the specifithe horizontal parts of which referably carry anti-frictlon rollers 18 un er whic act curved lever arms 19 pivoted at 20 to said end walls and coupled at 21 to links 22 pivoted at 23 to the hinged receptacle cover 24, so that as the cover is opened and closed the tra will be automatically raised and lowere and the cover also has a condensation drip pocket 25 provided w1th1n a flange 26 formed on or fixed to the cover near its hinge 27, all as described and claimed in my aforesaid companion patent application. Figs. 2 and 3 of the drawings more clearly show that when two resistance strips are used, the heating element support or grid 9 of insulating material is preferably provided in its opposite edges with two sets of slots or notches 28 and 29, the former being cut relatively deeper than the latter. The deeper slots 28, at each edge of the rid are directly opposite those, 29, of less epth at its other edge, or in other words, the slots at either edge are alternately arranged as regards depth. Wound upon the grld 9 within the slots are the two above mentloned strips 10 and 11, which are preferably made of high resistance ribbon material such as nichrome. One end of each strip 10, 11 is connected with a single resistor lead 30 held at one end of the grid, and the opposite ends of the strips 10, 11 are respectively connected with independent resistor leads 31, 32, held at the other end of the rid.

By far the larger portions of t e two resistance strips 10, 11 traverse the grid only on one side or face as comparatlvely little of their length passes angularly underneath the tongues a, formed between any two adjoining slots of like depth at opposite ed es of the grid, and therefore practically a l of each resistance strip is in heating contact with the mica sheet 6 of the receptacle bottom, and as the strips 10, 11 are each passed from the respective leads 30, 32, alternately through deep and shallow pairs of slots 28, 29 at opposite edges of the grid 9, the two strips are always safel held out of contact with each other at al portions of the grid, as clearly shown in ig. 3. Along its opposite slotted edges the grid 9 is cut away or rabbeted at 33 at its lower face to give room for passage of short portions of the resistance strips 10, 11, under the tongues a between pairs of slots 28, 29, without causing contact of the strip loops with the opposed cover plate 14 of the grid holding chamber 8, as shown in Fig. 2.

The resistor lead 30 is secured to the upper face of the grid 9 by a binding post 34, and the leads 31, 32 are respectively secured to the opposite end of the grid by binding posts 35, 36. The grid has holes 37, shown in Fig. 3, and through these holes pass the externally threaded ends of the above named bolts 12 which also pass through the cover plate 14. When the bolt nuts 13 are tightened below said plate they press it to the grid 9 and force its strips 10, 11 into intimate contact with the insulating mica plate 6 which imparts the heat of the energized strips uniformly from its entire area to the heavy cast metal bottom 5 of the rece tacle 1, thus insuring more perfect radiation of the heat from the strips through the receptacle bottom than would otherwise be obtalned.

The grid 9 has a central opening 38 at which is secured b bolts 39, a collar 40 of insulating materia and the retaining nuts or heads of the bolts are insulated from the grid coils 10, 11 by mica plates 41 placed over the bolts below the coils. The'collar fastening bolts 39 are shown in Figs. 1 and 3, and the mica plates 41 are more clearly shown in Fig. 3. A contact finger 42 is held to the collar 40 by a bolt 43 passing through the base portion of the contact which has a pendent outer end to which a binding post 44 is secured. A diametrically opposite bolt 45 holds to the collar 40 a contact plate 46 to the outer pendent end of which a binding post 47 is secured. The inner portion of plate 46 carries a pendent threaded metal sleeve 48 which enters the collar 40. Into this sleeve is screwed a conductive ring 49 fixed to a fuse carryin plug 50 of insulating material. A fusible element 51 on the plug 50 may be put in circuit with the ring 49, and a portion of said element passes over the inner end of the plug and may connect, through the contact 42 with the grid strips 10, 11 and the line circuit. When the plug 50 is screwed fully into the sleeve 48 the fusible element 51 forces the contact 42 snugly to the bottom of the receptacle 1, so that if the latter be electrically overheated because of evaporation of its sterilizing fluid contents, the heat imparted to the fusible element 51 will melt it and thus break the circuit leading to the resistance strips 10, 11, irrespective of any possible overload of current on the line. The arrangement of the fusible plug relatively to the receptacle 1, and the reslstance strips and the contacts is shown in my aforesaid companion applica tion, No. 178,535, and is herein recited only because of its relation to the hereinafter described and claimed system of leads and switch terminals for varying the character and intensity of current passed through the heating element strips 10, 11.

One side of the line or circuit is connected with the binding post 44 through a conductor 52, while the other side is connected with the strip 10 through the binding post 35 and conductors 53, 54. A switch 55 is held to the front of the receptacle 1 for controlling the supply of current to one or both of the resistance strips 10, 11 to provide the maximum, minimum, or intermedineeam ate-hea t, orto discontinue the The switch 55 comprises the contacts 56,; 57 and- 58 arranged to be engaged by the.

movable :switch arms or brushes 59, 60 and 61, and the contacts 62 and 63 arranged to be enga d byflthe movable switch arms 64 and 65w ich are insulated from the arms 59, 60 and 61. One end of the resistance strip 10 is connected with the contact 63 and also with the main line conductor 54 through the wire 53 whilethe opposite end of said strip is connected with the contact 56 through the wire 67. One end of the strip 11 is also con nected with the contact 56 through the wire 67, the latter having one end connected to the lead 30 to which both strips 10, 11 are connected. The contacts 58, 62 are both connected with the other end of the strip 11 by means of the wire 68, while the contact 57 is connected with the binding post 47 by means of the wire 69.

The switch in Fig. 3 is shown in open position. When the brushes 64 and 65 are moved into engagement with the contacts 62 and 63 respectively, as shown in Fig. 4, brush 59 will engage contact 57 and brushfil will engage contact 56, at which time the two strips or windings 10, 11 will be connec ed in parallel and the resistance brought to its maximum heating capacity. Withthe switch in this position, current will flow through main lme conductor 52, fuse 51, wire 69, brushes 59 and 61, wire 67, strips 10 and 11,*wir es 53 and 68 through brushes 65 and 64 respectively, and thence through main line conductor 54. The next succeeding position of the switch is indicated in Fig. 5 in which only the strip 10 is in C11- cu1t. With the switch in this position the capacity of the heater is reduced-to an intermediate point between high and low in which current passes through wire 69,

brushes 61 and 60, wire 67, strip 10, wire 53 and thence through conductor 54. The next succeeding position of the switch is indicated in Fig. 6, in which position the minimum capacity of the heater is reached. In this case the strips 10, 11 are connected in series and current will flow through main line conductor 52, wire 69, brushes 60 and 61, wire 68, strip 11, lead 31, stripvl0, wire 53 and thence through main line conductor 54. With the coils connected in series the heater is capable of bringing water to the boiling point within thereceptacle, although in this position the coils are reduced to their minimum heating capacity.

The particular manner of "winding overlapping the strips upon the grid as shown in Fig. 3 afi'ords an even distribution of heat over the entire bottom of the receptacle 1, regardless of whether or not the strips are in series or in parallel, or whether only one of said strips is in circuit. The 0b and ject in this case is to provide a plurality of strips or windings extending over a given area in such a manner that re rdless of whether or not one or more of t 0 strips is in circuit, the radiation therefrom will be evenly distributed over the entire surface which the strips are intended to heat.

It will be observed that the electric resistance heatin strips are woven across the upper face of tiie support, so that practically the entire radiating surface of each strip is used, thus avoiding the loss in energy which occurs where the resistance elements. are

wound helically around their supports,

whereby more than one-half of their length is out of contact with the surface to be heated. Another is directed is the act that the convolutions of the two strips alternate from end to end of the support, thus causing an even distribution of the heat when one strip alone is utilized. ,In other words, where a plurality of'strips is employed the convolutions of each are so disposed that all of the strips cover, or are spread over, the same given area the intent and purpose being to heat the bottom of the sterilizer equally at all points, as this insures a quicker heating of the water, or other sterilizing medium which may be placed in the receptacle and maintains it at the desired temperature with the minimum amount of current consumption.

A second lowermost cover plate 70, preferably has an upturned edge flange fitting closely within the pendent edge flan e 7 of the receptacle bottom plate 5, and a so has a cupped central portion which accommodates the insulating collar 40 and has a central opening through which is passed the body portion of the fuse plug 50, and also has a small opening for passage of the line circuit. wires 52, 54, all as best shown in Fig. 2. The plate 70 is shown secured by screws 71 passin upwardly into the grid fastening bolt en s 12. The plate 70 guards from dust and injury the Wll'e connections to the grid strips 10, 11 and to the switch 50, and also assists in preventing objectionable downward radiation of heat from the ap aratus.

t will be understood that within the scope of this invention the heating element insulating support or grid 9 is not necesoint to which attention sarily slotted at opposite edges which may I loops.

electri al-h m f el m n -sk hasmaximum'e ciencypj- 1 I 'I claim, asmyinventionfr" j I 1. electri heater-'- lenient comprising ftasupport havingftof comparatively small thusgroducingsn c for its a was! a is or w w "and anelectricresistancestrip oo go: oi; the su crossing portions of-the strip 2; Aniel'ectric. heater 'eifiiii comprising a support jhaving tongueslat its opposite un er "and 'across' the tongues and traversing but. oneface of the support in its pas- I sage from a 'tongue'at onejedge' of the supof g the support and accommodating the' tongue .c

striploops Q and a cover plate held at l'portto a tongue at its opposlte edge, and

support having face rabbe'ts or recesses making thetongues thinner than the main body principally upon but one face of the support.

4. In an electric heater, the combmatmn with a support, a plurality of resistance er and across thetongucs and traversing.

' ibut one face of I the .sup in fr 1n,a tongueat eone it o i tongue at its 'o' pos1t e fedg'e, -sa1 port having face rab w v i the tongues thmner'thanthe mainbody o -.p

- the supportand accommodating the tongue.

ge with asupport having trio resistance strips and an'electric resistance strip looped and a second resistance strip assed over t strips ms ser ent, was convolutions overl p033 the convolutions of one strip being 10- one face of th between those of theother strip, said support having provision 'forthe loops of the convolutions to holdthoee of one strip out of. contact with those of the other. strip. 1 5. In an electric heater the combination ah n u 1 ts alternate deep and [sow otsini'op ,0 secloo into alternate convolutions, the loops 0 each strip bcin assed through alternate pairs of dee an shatllow, slots. and by them held out 0 contac I 6. In an electric heater the combination with a support having aternate deep and shallow s ots in 'itsopposite' edges, of an electric resistance stri passed over the face of j the support and ooped through adjacent shallow slots at one edge of the supportand' adjacent deep slots at the other edgle, e face of the support between t e convolutions of the first strip and looped through the pairsof slots unoccupied by the first strip. 7. In an electric heater, the combination with a supportcomposed of a sheet of insulatingimaterial' having two parallel edges each provided with open ended alternately disposed shallow and dee ilslots, the deeper slots in one ed e being eac located in opposition to a she ow slot in the other edge, of two; electric resistance heating strips disosed in alternate convolutions across one ace of the support,said convolutions being held in spaced relation and out of contact b looping them alternately throu h the she. low slots at one edge and the cop slots at the other edge of the support.

"ALBERT H. JESSUP,

e sup 

